The Induction Efficiency Of Different Induced Lines To Different Genotypes Of Maize

The double haploid technology,known as DH technology,mainly uses haploid induced lines to induce haploid.The DH technology only needs 2-3 generations to quickly select a complete homozygous inbred line,which significantly shortens the breeding cycle,while the traditional method of breeding inbred lines needs at least 6-8 generations to obtain about 99% homozygosity.In this study,three haploid induction lines were hybridized with different genotypes,and the effects of different inducers,different genotypic materials,different ways of doubling and different locations on the induction efficiency of haploid were discussed in order to provide reference for the application of haploid breeding technology in the future.The main results and conclusions are as follows:(1)In the experiment of induction in Hainan and Guizhou,there was significant difference in induction rate between different genotypic materials.Among the seven maternal materials selected in the 2018 Hainan hybrid induction experiment,the average induction rates of R2 and W3 were relatively high,which were 3.50% and 3.56% respectively,significantly higher than 1.71% of W5.Among the 8 maternal materials selected in the cross induction experiment in Guizhou in 2019,the average induction rates of W7 and W8 were 4.06% and 4.05% respectively,significantly higher than that of R4(2.28%);The average induction rate of temperate materials are higher than tropical materials.(2)In the experiment of induction in Hainan and Guizhou,the induction rates of three induction lines were significantly different.In Hainan induction experiment in 2018,the average induction rate of Stock6 and N548-1 was 3.22% and 3.14% respectively,which was significantly higher than 2.33% of W1619;In the induction experiment in Guizhou in 2019,the average induction rate of N548-1 was the highest,which was 4.15%,significantly higher than that of Stock 6 and W1619,among which,W1619 was the lowest,only 2.53%.The two-year hybridization experiment showed that the average induction rate of induction line N548-1 was the highest,followed by Stock6,W1619.(3)There are great differences in haploid doubling rate among different genotypic materials,different doubling methods and different sites.In the experiment of haploid doubling in Guizhou,the natural doubling and chemical doubling of R2 were the best,and the seed setting rates of R2 were 6.480% and 8.063% respectively,which were significantly higher than other materials;In Gansu haploid doubling test,the natural doubling effect of material W2 is the best,and its haploid seed setting rate is 1.27%;The chemical doubling effect of material W5 is the best,and its haploid seed setting rate is 6.663%,which is significantly higher than that of other materials;In the haploid doubling experiment in Hainan,the doubling effects of natural doubling and chemical doubling of material R1 were the best,and the haploid seed setting rates were 3.163% and 7.027%,respectively.Among them,the seed setting rate of R1 natural doubling was significantly higher than that of W6,and that of chemical doubling was significantly higher than that of R4,R5,W8 and w9.Under different locations and different doubling methods,the chemical doubling effect of Guizhou,Gansu and Hainan was better than that of natural doubling,and the doubling rates of haploid natural doubling and chemical doubling in Guizhou were higher than those in Gansu.